The present invention relates to a new and improved method of fabricating conveyor or feed worms, especially conveyor worms or screws used in plastic processing machines, which are of the type comprising a tough steel core and a high wear resistant metal plating.
The high loads and the therewith associated pronounced wear to which, in particular, there are subjected the webs of conveyor or feed worms, has given rise to attempts to find solutions to improve the service life of such conveyor worms or screws. Thus, for instance, it is known in this art to subject the surface regions of conveyor or feed worms employed in plastic processing to a hardening treatment by techniques such as case hardening, nitriding, ion nitriding and so forth, and, in particular, to reinforce or armor the webs and, if desired, also the worm tips by applying particularly wear resistant weld deposits. While it was possible in this manner to attain a decisive improvement, nonetheless such techniques were associated with a relatively great amount of work, and, accordingly, increased fabrication costs.